package di

import (
	"fmt"
	"io"
	"os"
)

func Greet(b io.Writer, s string) {
	fmt.Fprintf(b, "Hello, %s", s)
}

func main() {
	Greet(os.Stdout, "yy")
}

func Fact(n int) int {
	if n == 0 {
		return 1
	}
	return Fact(n-1) * n
}
